The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Necturus maculosus
Necturus maculosus
Native Transplant

Copyright Info
Necturus maculosus (Rafinesque, 1818)

Common name: Mudpuppy

Taxonomy: available through www.itis.govITIS logo

Size: generally 20 - 33 cm

Native Range: Sporadically distributed from the southeastern U.S. north to New York, Vermont and Quebec and west to North Dakota and Manitoba.

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Necturus maculosus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
ME193919932East Branch Penobscot River; Lower Kennebec River
MA197120051Ashuelot River-Connecticut River
NH202020201Ammonoosuc River-Connecticut River
VT200120162Black River-Connecticut River; Waits River-Connecticut River

Table last updated 7/24/2024

† Populations may not be currently present.

Ecology: Found in clear lakes, rivers and streams, and some weedy, turbid and mud-banked streams.  It lingers in shallow aquatic habitats under rocks and logs and swims deep in lakes on occasion.  Primarily nocturnal, but is known to venture out during daytime in cloudy or sheltered water.  Females construct underwater nests and lay up to 100 eggs (average 48-60) during May and June.

Means of Introduction: The New England populations are releases or escapes from college biology programs.

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

References: (click for full references)

Reigle, N. J., Jr. 1967.  The occurrence of Necturus in deeper waters of Green Bay.  Herpetologica 23:232-233.

Author: McKercher, E.

Revision Date: 9/14/2011

Citation Information:
McKercher, E., 2024, Necturus maculosus (Rafinesque, 1818): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=156, Revision Date: 9/14/2011, Access Date: 7/24/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/24/2024].

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